Datasheet
LTC3731
5
3731fc
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= V
RUN/SS
= 5V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Differential Amplifier
A
V
Differential Gain 0.995 1.000 1.005 V/V
V
OS
Input Offset Voltage Magnitude IN
+
= IN
–
= 1.2V, I
OUT
= 1mA, Input Referred; Gain = 1 0.5 5 mV
CMRR Common Mode Rejection Ratio 0V < IN
+
= IN
–
< 5V, I
OUT
= 1mA, Input Referred 50 70 dB
I
CL
Output Current Sourcing 10 40 mA
GBP Gain-Bandwidth Product I
OUT
= 1mA 2 MHz
SR Slew Rate R
L
= 2k 5 V/µs
V
O(MAX)
Maximum High Output Voltage I
OUT
= 1mA V
CC
– 1.2 V
CC
–0.8 V
R
IN
Input Resistance Measured at IN
+
Pin 80 kΩ
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
LTC3731CG/LTC3731IG: T
J
= T
A
+ (P
D
• 95°C/W)
LTC3731CG/LTC3731IG: T
J
= T
CASE
+ (P
D
• 32°C/W)
LTC3731CUH/LTC3731IUH: T
J
= T
A
+ (P
D
• 34°C/W)
Note 3: The IC is tested in a feedback loop that includes the differential
amplifier loaded with 100µA to ground driving the error amplifier and
servoing the resultant voltage to the midrange point for the error amplifier
(V
ITH
= 1.2V).
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 5: The minimum on-time condition corresponds to an inductor
peak-to-peak ripple current of ≥40% of I
MAX
(see minimum on-time
considerations in the Applications Information Section).
Note 6: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.